A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interact...A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interactions between the two- dimensional silicon layer, commonly known as silicene, and the layered SnS2 template are investigated by analyzing different configurations of silicene. The calculated thermodynamic phase diagram suggests that the most stable configuration of silicene on SnS2 belongs to a family of structures with Si atoms placed on three different planes; so-called dumbbell silicene. This particular dumbbell silicene structure preserves its atomic configuration on SnS2 even at a temperature of 500 K or as a ＂flake＂ layer （i.e., a silicene cluster terminated by H atoms）, thanks to the weak interactions between the silicene and the SnS2 layers. Remarkably, an electric field can be used to tune the band gap of the silicene layer on SnS2, eventually changing its electronic behavior from semiconducting to （semi）metallic. The stability of silicene on SnS2 is very promising for the integration of silicene onto semiconducting or insulating substrates. The tunable electronic behavior of the silicene/SnS2 van der Walls heterostructure is very important not only for its use in future nanoelectronic devices, but also as a successful approach to engineering the bang-gap of layered SnS2 paving the way for the use of this layered compound in energy harvesting applications.展开更多
Silicene, the silicon counterpart of graphene, has been successfully grown on metallic substrates such as Ag（111）, ZrB2（0001）, and Ir（111） surfaces. However, characterization of its electronic structure is hampe...Silicene, the silicon counterpart of graphene, has been successfully grown on metallic substrates such as Ag（111）, ZrB2（0001）, and Ir（111） surfaces. However, characterization of its electronic structure is hampered by the metallic substrate. In addition, potential applications of silicene in nanoelectronic devices will require its growth on or integration with semiconducting and insulating substrates. We herein present a review of recent theoretical works regarding the interaction of silicene with non-metallic templates, distinguishing between the weak van-der-Waals-like interactions of silicene with, for example, layered metal （di）chalcogenides, and the stronger covalent bonding between silicene and, for example, ZnS surfaces. We then present a methodology to effectively compare the stability of diverse silicene structures using thermodynamics and molecular dynamics density functional theory calculations. Recent experimental results on the growth of silicene on MoS2 are also reported and compared to the theoretical predictions.展开更多
文摘A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interactions between the two- dimensional silicon layer, commonly known as silicene, and the layered SnS2 template are investigated by analyzing different configurations of silicene. The calculated thermodynamic phase diagram suggests that the most stable configuration of silicene on SnS2 belongs to a family of structures with Si atoms placed on three different planes; so-called dumbbell silicene. This particular dumbbell silicene structure preserves its atomic configuration on SnS2 even at a temperature of 500 K or as a ＂flake＂ layer （i.e., a silicene cluster terminated by H atoms）, thanks to the weak interactions between the silicene and the SnS2 layers. Remarkably, an electric field can be used to tune the band gap of the silicene layer on SnS2, eventually changing its electronic behavior from semiconducting to （semi）metallic. The stability of silicene on SnS2 is very promising for the integration of silicene onto semiconducting or insulating substrates. The tunable electronic behavior of the silicene/SnS2 van der Walls heterostructure is very important not only for its use in future nanoelectronic devices, but also as a successful approach to engineering the bang-gap of layered SnS2 paving the way for the use of this layered compound in energy harvesting applications.
文摘Silicene, the silicon counterpart of graphene, has been successfully grown on metallic substrates such as Ag（111）, ZrB2（0001）, and Ir（111） surfaces. However, characterization of its electronic structure is hampered by the metallic substrate. In addition, potential applications of silicene in nanoelectronic devices will require its growth on or integration with semiconducting and insulating substrates. We herein present a review of recent theoretical works regarding the interaction of silicene with non-metallic templates, distinguishing between the weak van-der-Waals-like interactions of silicene with, for example, layered metal （di）chalcogenides, and the stronger covalent bonding between silicene and, for example, ZnS surfaces. We then present a methodology to effectively compare the stability of diverse silicene structures using thermodynamics and molecular dynamics density functional theory calculations. Recent experimental results on the growth of silicene on MoS2 are also reported and compared to the theoretical predictions.
